package com.kuang.service;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLEncoder;


public class fileServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//        1.要获取下载文件的路径
        String realPath="D:\\web\\javaWeb\\03-Response\\target\\classes\\秦疆.png";
        // String realPath = this.getServletContext().getRealPath("/1.jpg");
        System.out.println((("文件的下载路径为：" + realPath)));
//        2.下载的文件名是啥？
        String fileName = realPath.substring(realPath.lastIndexOf("\\") + 1);

//        3.设置想办法让浏览器能够支持下载我们需要的东西
        resp.setHeader("Content-Disposition","attachment;filename="+ URLEncoder.encode(fileName,"UTF-8"));
//        4.获取下载文件的输入流

        FileInputStream inputStream = new FileInputStream(realPath);

//        5.创建缓冲区
        int len;
        byte[] buffer = new byte[1024];

//        6.获取OutputStream对象
        ServletOutputStream outputStream = resp.getOutputStream();

//        7.将FileOutputStream流写入到bufer缓冲区
//        8.使用OutputStream将缓冲区中的数据输出到客户端！
        while((len=inputStream.read(buffer))>0){
            outputStream.write(buffer,0,len);

        }
            inputStream.close();
            outputStream.close();
        }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}
